A problem facing the nuclear industry which has received much attention is how to dispose of nuclear so that they will not contaminate the environment with radioactivity.
In the past, methods have been offered for the fixation of radioactive materials in non-radioactive solids of low water leachability, such as the incorporation of fission by-products in glass, ceramic glaze, or rock-like materials. Examples of such methods are disclosed by Arrance in U.S. Pat. No. 3,093,593 and Spector in U.S. Pat. No. 3,110,557. However, since these methods require high temperature for the fixation reaction, the lower boiling metal oxides, some of which possess a high level of radioactivity, escape from the system. Similarly, Conner, in U.S. Pat. No. 4,518,508 solidified nuclear wastes by mixing with a dry water-reactive solidification agent comprising cement, a dry water absorbent material and a powdered alkali metal silicate. But, none of these methods provide an outer layer of non-radioactive material. In U.S. Pat. No. 4,404,129, Penberthy et al. teach a non-radioactive outer layer, but, again, this method requires heating of the nuclear wastes to high temperatures.
Heinemann et al. in U.S. Pat. No. 3,213,031 teach of containing nuclear wastes in a vessel and then coating the vessel with a sealant comprising a solid, non-radioactive mixture of a metal oxide and an elemental metal. That method, however, does not allow for prior production of completed vessels, nor does it necessarily utilize readily available starting products.